The objectives of this research program are to elucidate the endocrine and neuroendocrine control systems which govern reproductive processes in a representative primate, the rhesus monkey. The hypothalamic control of gonadotropin secretion is of central interest. BIBLIOGRAPHIC REFERENCES: Peckham, W.D. and E. Knobil. The effects of ovariectomy, estrogen replacement and neuraminidas treatment on the properties of the adenohypophyseal glycoprotein hormones of the rhesus monkey. Endocrinology 98:(4)1054, 1976. Peckham, W.D. and E. Knobil. Qualitative changes in the pituitary gonadotropins of the male rhesus monkey following castration. Endocrinology 98:(4)1061, 1976.